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61.
This paper distinguishes among three types of generosity of social security systems: average generosity, generosity towards early retirement and generosity towards the poor. On the basis of theoretical predictions, it examines the statistical correlations among those types of generosity for 14 OECD countries over the period 1985–2000. It also shows how they have evolved over time and tries to relate this evolution to the process of economic integration. There are three main findings, the first one being a positive relation between average social security spending and poverty alleviation. There is the negative relation between average spending and inequality reduction. Finally, over the period 1985–1995 one sees that poverty alleviation increases on average, but to a degree that decreases with economic openness.  相似文献   
62.
RÉSUMÉ ** :  Cet article cherche à estimer, pour un échantillon issu de sept pays européens, le différentiel de satisfaction dans l'emploi entre les secteurs à but non lucratif et à but lucratif, et à en examiner les causes. La richesse des données utilisées permet, contrairement aux études antérieures, de prendre en compte les différences de caractéristiques d'emploi entre les deux secteurs. Les résultats obtenus révèlent que la plus grande satisfaction dans l'emploi des salariés du secteur à but non lucratif résulte principalement de caractéristiques mesurant l'autonomie et l'intérêt de l'emploi et d'une plus grande satisfaction vis-à-vis de leur autonomie et de la nature du travail qu'ils effectuent, éléments susceptibles de contribuer au développement de la motivation intrinsèque des salariés.  相似文献   
63.
Accurate solar forecasts are necessary to improve the integration of solar renewables into the energy grid. In recent years, numerous methods have been developed for predicting the solar irradiance or the output of solar renewables. By definition, a forecast is uncertain. Thus, the models developed predict the mean and the associated uncertainty. Comparisons are therefore necessary and useful for assessing the skill and accuracy of these new methods in the field of solar energy.The aim of this paper is to present a comparison of various models that provide probabilistic forecasts of the solar irradiance within a very strict framework. Indeed, we consider focusing on intraday forecasts, with lead times ranging from 1 to 6 h. The models selected use only endogenous inputs for generating the forecasts. In other words, the only inputs of the models are the past solar irradiance data. In this context, the most common way of generating the forecasts is to combine point forecasting methods with probabilistic approaches in order to provide prediction intervals for the solar irradiance forecasts. For this task, we selected from the literature three point forecasting models (recursive autoregressive and moving average (ARMA), coupled autoregressive and dynamical system (CARDS), and neural network (NN)), and seven methods for assessing the distribution of their error (linear model in quantile regression (LMQR), weighted quantile regression (WQR), quantile regression neural network (QRNN), recursive generalized autoregressive conditional heteroskedasticity (GARCHrls), sieve bootstrap (SB), quantile regression forest (QRF), and gradient boosting decision trees (GBDT)), leading to a comparison of 20 combinations of models.None of the model combinations clearly outperform the others; nevertheless, some trends emerge from the comparison. First, the use of the clear sky index ensures the accuracy of the forecasts. This derived parameter permits time series to be deseasonalized with missing data, and is also a good explanatory variable of the distribution of the forecasting errors. Second, regardless of the point forecasting method used, linear models in quantile regression, weighted quantile regression and gradient boosting decision trees are able to forecast the prediction intervals accurately.  相似文献   
64.
This paper presents a theoretical model of conflict between two players, with intervention by a peacekeeping force. Peacekeepers are treated as a military contingent, capable of taking sides, acting as a third (independent) side in the war or remaining inactive, depending on circumstances. This departs from previous models, in which peacekeeping was no more than a parameter affecting players' fighting costs. The main result is an optimal deployment strategy by peacekeepers, detailing the nature and level of intervention required under different circumstances; this strategy results in the lowest possible level of warfare between the two antagonists. The credible threat of force (rather than mere intervention) is the strategy's key component.  相似文献   
65.
Background Population aging brings up a number of health issues, one of which is an increased incidence of herpes zoster (HZ) and its complication, post-herpetic neuralgia (PHN). Zostavax vaccine has recently become available to prevent HZ and PHN. This study evaluates the cost-effectiveness of vaccination against HZ in Spain considering a vaccination of the population aged 50 years and older and comparing this to the current situation where no vaccination is being administered.

Methods An existing, validated, and published economic model was adapted to Spain using relevant local input parameters and costs from 2013.

Results Vaccinating 30% of the Spanish population aged 50 years and older resulted in €16,577/QALY gained, €2025/HZ case avoided, and €5594/PHN case avoided under the third-party payer perspective. From a societal perspective, the ICERs increased by 6%, due to the higher price of the vaccine. The number needed to vaccinate to prevent one case was 20 for HZ, and 63 for PHN3. Sensitivity analyses showed that the model was most sensitive to the HZ and PHN epidemiological data, the health state utilities values, and vaccine price used.

Conclusion Considering an acceptable range of cost-effectiveness of €30,000–€50,000 per QALY gained, vaccination of the 50+ population in Spain against HZ with a new vaccine, Zostavax, is cost-effective and makes good use of the valuable healthcare budget.  相似文献   
66.
Béal  Mathieu  Sabadie  William  Grégoire  Yany 《Marketing Letters》2019,30(3-4):293-305
Marketing Letters - Relationship length and its implications for service recovery have rarely been quantified in terms of cross-buying and customer profitability. Based on a sample of 935 customers...  相似文献   
67.
This paper considers practically appealing procedures for estimating intraday volatility measures of financial assets. The underlying microstructure model accommodates the inherent properties of ultra high‐frequency data with the assumption of continuous efficient price processes. In this model, microstructure noise and trading times are endogenous but do not only depend on the prices. Using the (observed) last traded prices of the assets, we develop a new approach that enables to approximate the values of the efficient prices at some random times. Based on these approximated values, we build an estimator of the integrated volatility and give its asymptotic theory. We also give a consistent estimator of the integrated covariation when two assets (asynchronous by construction of the model) are observed.  相似文献   
68.
69.
Connecting science with policy has always been challenging for both scientists and policymakers. In Ghana, Mali and Senegal, multi-stakeholder national science-policy dialogue platforms on climate-smart agriculture (CSA) were setup to use scientific evidence to create awareness of climate change impacts on agriculture and advocate for the mainstreaming of climate change and CSA into agricultural development plans. Based on the platforms' operations and achievements, we used semi-structured questionnaire interviews and reviewed technical reports produced by the platforms to analyse how their modes of operation and achievements improve understanding of the science-policy interfaces between agricultural and climate change decision making. Results showed that these platforms constitute an innovative approach to effectively engaging decision-makers and sustainably mainstreaming climate change into development plans. Effective science-policy interaction requires: (a) institutionalizing dialogue platforms by embedding them within national institutions, which improves their credibility, relevance and legitimacy among policymakers; (b) two-way communication, which contributes substantially to the co-development of solutions that address climate change vulnerabilities and impacts; and (c) relevant communication products and packaging of evidence that aligns with country priorities, which facilitates its uptake in policy-making processes. We conclude with a framework of sustainable operation for such platforms based on lessons learnt in the three countries.  相似文献   
70.
In practice, the choice of using a local volatility model or a stochastic volatility model is made according to their respective ability to fit implied volatility surfaces. In this paper, we adopt a different point of view. Indeed, using a purely statistical methodology, we design new procedures aiming at testing the assumption of a local volatility model for the price dynamics, against the alternative of a stochastic volatility model. These test procedures are based only on historical data and do not require any calibration procedures via option prices. We also provide a convincing simulation study and an empirical analysis on future contracts on interest rates.  相似文献   
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